The present invention relates to a retractable folding top for motor vehicles, having a top frame which comprises a material retaining hoop forming the lower termination of the top and has a top storage box lid for accommodating the folded top. The top storage box can be closed by a top storage box lid, following which it is held shut by closure means. The folding top has a position of rest of the material retaining hoop on the top storage box lid when the top is closed. The material retaining hoop is non-continuously connected to the top storage box lid via a closure arrangement.
Such a folding top is already known from German Patent Document 948,121, in which two closures are provided on the top storage box lid to hold down the material retaining hoop. The closure hooks of these closures, arranged on the material retaining hoop, each engages behind an associated retaining plate of the top storage box lid. Since the closure hooks are articulated on the material retaining hoop by means of gripping levers, the closures can be locked and unlocked by directionally adjusted pivoting of their gripping levers.
Because of the functional principle of these hook closures, manual actuation of the known folding top is relatively inconvenient, since both gripping levers have to be operated both during opening and during closing of the top.
Increasingly, therefore, twist-type spring locks are being used for locking frame components of folding tops which are conventional today. The twist-type spring locks lock automatically as a result of the pressing-down of the frame component onto the associated connecting component, with the forked latch of the twist-type spring locks being rotated by the closure pin, which impacts on it, into its closed position in which it is retained by a spring-loaded safety catch.
If, then, the two hook closures of the previously known folding top were to be replaced by corresponding twist-type spring locks of a conventional type, a two-point locking, and hence simplification of operation, would in principle be possible by absolutely uniform pressing-down of the material retaining hoop onto the top storage box lid. However, the center of the material retaining hoop is accessible only with difficulty from the vehicle side, as a result of which laterally offset pressing-down of the material retaining hoop is induced.
With laterally offset pressing-down of the material retaining hoop, the material retaining hoop may twist somewhat, as a result of which only the twist-type spring lock disposed on the operating side enters into its locking position. If, in this case, the closure pin on the opposite side is not wedged, and so locked, in the associated closure housing, the material retaining hoop can now be brought into its definitively locked position of rest on the top storage box lid by pressing down on the side which is still open. Since this requires the operator to move to the other side of the vehicle, operation of the folding top remains relatively inconvenient despite the twist-type spring locks.
An object of the present invention is to provide a folding top in which the operation of the folding top is significantly simplified in the locking of the material retaining hoop on the top storage box lid.
This and other objects are achieved by the present invention which provides a retractable folding top for motor vehicles which has a top frame having a material retaining hoop forming a lower termination of the top, a top storage box for accommodating the folded top, a top storage box lid for closing the top storage box, a closure for holding shut the top storage box lid, the top having a position of rest of the material retaining hoop on the top storage box lid when the top is closed, and a closure by which the material retaining hoop is non-continuously connected to the top storage box lid. The closure arrangement between the material retaining hoop and the top storage box lid has only a single, first closure which is arranged in a central region of an overlap zone between the top storage box lid and the material retaining hoop.
The locking of the material retaining hoop from one side of the vehicle is comfortably possible as a result of the omission of additional closures. The nonduplication of the closure arrangement simultaneously results in a significant cost advantage, since closures, being precision components, require a significant production engineering effort and are hence expensive.
On the other hand, single-point locking of the material retaining hoop on the associated top storage box lid is not without its problems, since when the folding top is closed, the tensile forces in the top cover must be transmitted to a single point on the top storage box lid and absorbed thereby. The top storage box lids of conventional antibuckling rigidity are not readily able to withstand this stress.
When the top storage box lid is fitted counter to the material retaining hoop, the closure for holding down the material retaining hoop is advantageously arranged behind the point at which the top storage box lid is secured to the bodywork, as a result of which bending of the top storage box lid on the lock side is prevented. However, the material retaining hoop will overlap the top storage box lid closer to the hinge side, as a result of which the closure for the material retaining hoop will be at a distance, in the longitudinal direction of the vehicle, from the point at which the top storage box lid is locked to the bodywork.
In order that the top storage box lid does not bulge under the influence of the tensile forces of the top cover, partial reinforcement of the top storage box lid is provided in the region in which the closure is arranged, and this holds down the material retaining hoop.
To permit a reinforcement of the top storage box lid which is particularly favorable in terms of weight, a bearing connection which is effective when the top storage box lid is closed is provided between the reinforcement zone of the top storage box lid and the adjoining bodywork, and prevents upward bulging of the reinforcement zone.
Advantageously, the bearing connection comprises a support lever which is attached to the top storage box lid and is moved therewith, and a counter-bearing arranged on the bodywork side, behind which, when the top storage box lid is closed, the supporting lever engages in a force-absorbing manner.
So that the supporting lever should take up only a small amount of space in the top storage box lid, an embodiment of the invention provides as the supporting lever a hoop curved in the manner of a hinged lever, which is guided in the counter-bearing, passing through the counter-bearing.
In order to prevent the end region of the supporting lever which passes through the counter-bearing from producing unpleasant noises in the course of its advance, the end region can interact with a pin of the counter-bearing, the rotatably mounted pin being caused, as a consequence of the advance of the end region resting on its periphery, to execute a corresponding rotation in rolling contact.
The reinforcement zone can, in addition to its static stress during driving operation, also be dynamically stressed as a consequence of the slipstream passing over the top, which is alternately associated with the upward bulging of the reinforcement zone and with the downward bulging of this reinforcement zone.
So that the buckling stress on the reinforcement zone in both directions can be absorbed by the supporting lever, a claw-type connection of the end region in the counter-bearing is provided in an embodiment of the invention.
For the claw-type connection, wedge-shaped surfaces which impact one upon the other on the long side of the end region opposite the engaging side are provided in certain embodiments.
To enable tolerances in the unfinished structure of the vehicle to be compensated, in an embodiment of the invention, the counter-bearing is arranged on a vertically adjustable holder, and an element of the counter-bearing is provided with a wedge-shaped surface adjustably mounted on the holder.
The adjustable element with a wedge-shaped surface preferably comprises a plastics wedge, since the impact noises of the wedge-shaped surface on the end region of the supporting lever are attenuated thereby.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.